1. Field of the Invention
The present invention relates to a waterproof and/or water-resistant camera, more precisely, it relates to a waterproof and/or water-resistant camera having a photographing lens barrel which is movable in the optical axis direction of the camera.
2. Description of Related Art
A water-resistant camera which does not allow drips of rain or water to go into the camera e.g. in the rain or on the shore, and a waterproof camera which can take pictures even in shallow water, e.g. in a swimming pool, or in seawater near the edge of a beach, are both available on the market.
There have been attempts to develop a zoom camera which is waterproof and/or water resistant. One solution is to position a seal member, such as an O-ring, between a photographing lens barrel, which is movable to project from or retract into an opening formed in a front wall of a camera body, and the opening, so that the O-ring is brought into close contact with the inner periphery of the opening and the outer periphery of the photographing lens barrel at the outer surface and the inner surface of the O-ring respectively, thereby producing a watertight mechanism.
However, in order to enhance the watertightness between the O-ring and the inner periphery of the opening, it is necessary to minimize the clearance between the photographing lens barrel and the inner periphery of the opening so to firmly press the O-ring against the inner periphery of the opening. This causes the O-ring to also be strongly pressed against the outer periphery of the photographing lens barrel, resulting in an increase in the slide resistance of the movable photographing lens barrel. Therefore, no smooth movement of the photographing lens barrel can be ensured.
To avoid this, it is necessary to decrease the contact pressure of the O-ring against the inner periphery of the opening. This, however, decreases the watertightness between the O-ring and the inner periphery of the opening and between the O-ring and the outer periphery of the photographing lens barrel.